The traditional computer, such as 286, 386, and 486, is provided with a LED displaying unit, as shown in FIG. 1. The LED displaying unit is usually mounted on the front panel of the computer case and is capable of indicating the operation speed, such as 20 or 33 MHz, of the computer system. So, the user may know the performing status of the computer system. Normally, the values on the LED displaying unit are fixed once the computer is installed and can not be changed by the user if the CPU is replaced with another one or upgraded.
The traditional LED displaying unit can only show that the central processing unit of the computer is operated in TURBO or non-TURBO mode. The operation mode indicated on the displaying unit is normally set by the computer manufacturer, and does not indicate the real performing efficiency of the computer system during working. This results in inconvenience for different types of CPUs , such as 386, 486, Pentium, and so on. That is, once the CPU of the computer is changed, the LED displaying unit must be manually set in accordance with the new CPU. The LED displaying unit with fixed value to show the CPU speed is hard to support the modern computer system because there are so many types of CPU with different operation speeds. Therefore, such LED displaying unit is not used in the current computer system incorporated advanced central processing unit, such as Pentium processor issued by Intel corporation.
A displaying module on the outer case of the computer is greatly needed to directly displaying the internal system information, the configuration oft he computer, and peripheral devices used of the computer during power-on or power-off without opening the case to examine.